Russian space shuttle story at ArsTechnica

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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 2:26 pm

Okay, my understanding of gravity wells might be a little rusty/off, but it was my understanding that even if you were on the moon, you were technically still in Earth's gravity well.

The trick to getting into staying in space isn't about getting so far away that the gravity doesn't affect you, but moving fast enough to get into orbit. Anything getting out of Earth's gravity well probably isn't coming back, like the Voyager probes and the Curiosity rover.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 2:30 pm

Captain Ned wrote:
cphite wrote:Correct. The rocket science aspect is fairly well settled. It's the medical stuff that's the real challenge.

You're still not getting the importance of Earth's gravity well. Yes, we know HOW to lift stuff/people to Earth escape velocity, though we've not sent a human at that speed since December 7, 1972. It's still expensive in fuels and rocket parts, it has an inherent failure rate that will never be zero, and it's damned uncomfortable to boot.

Getting things/people out of Earth's gravity well without using chemical rockets will be the first great step forward. Personally, I've always believed the space elevator to be the best method for this as it greatly reduces the needed mass to be lifted and allows for electrical power to provide the required force. A station above geosync (most elevators are designed with the center of mass at geosync) would greatly reduce the propulsive needs for escape velocity.


I am getting that.

But the claim was this: "It isn't the lack of artifical gravity in space that's the problem, it's the abundance of natural gravity keeping us of out of it. "

And that simply isn't a true statement. The act of putting people into space is wildly expensive, yes; but it's not the primary thing that's holding us back from establishing a true foothold in space. And with continued innovation, there is every reason to expect that the costs of putting people into space should come down.

It is much less likely that we are going to see advancements that solve the problems of long term stays in micro-gravity.

A trip to Mars is expected to take seven months. The longest any human being has ever spent in space has been a little more than a year. So anyone going to Mars is going to spend seven months in zero gravity followed by - probably forever - very low gravity on Mars itself. What evidence there is suggests that these people will eventually develop health issues related to low gravity.

That, in addition to radiation, is the major road block to humans doing much more in space than we've done already. Regardless of how good we get at putting people up there.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 2:37 pm

With respect to the gravity issue on long space flights, I believe the current thinking is that you have to create an artificial gravity environment for the astronauts to live in. I know that this can be done with centrifugal force as well as other possible means, but I confess I'm poorly read on the subject.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 2:50 pm

Captain Ned wrote:Well, if we're going to throw radiation around let's just go straight to Orion


Orion, while really neat, would be spectacularly expensive because of the number of nuclear bombs you'd be setting off, and is overkill for the inner solar system.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 2:52 pm

Lucky Jack Aubrey wrote:With respect to the gravity issue on long space flights, I believe the current thinking is that you have to create an artificial gravity environment for the astronauts to live in. I know that this can be done with centrifugal force as well as other possible means, but I confess I'm poorly read on the subject.

The problem with centrifuge systems is the need for them to be very large (or small capsules tethered and rotating at a hefty distance from each other) to avoid the tidal and Coriolis forces one would encounter in trying to move around in the centrifuge. Someone's worked out the necessary radius for comfort but I can't find it at the moment.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 3:16 pm

I'll chime in and say that the escaping earth's gravity is well understood, it is just ridiculously expensive. And with all of our tech, I'd wager that the $$/pound to put a satellite into orbit has not come down at all since the 1960's. That's what the shuttle was supposed to accomplish by bringing the cost down to a fraction of what it was by going to reusable aircraft versus disposable.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 4:49 pm

superjawes wrote:The trick to getting into staying in space isn't about getting so far away that the gravity doesn't affect you, but moving fast enough to get into orbit.

See http://what-if.xkcd.com/58/
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 5:15 pm

Usacomp2k3 wrote:That's what the shuttle was supposed to accomplish by bringing the cost down to a fraction of what it was by going to reusable aircraft versus disposable.

That, and launching 50+ times per year. How anyone ever believed the projected Shuttle launch rates is a mystery. Where would we (the USA) be today if we'd done what the Soviets/Russians did and just standardize on the Saturn family as they standardized on the R-7 family for man-rated launchers? Better yet, the tens of thousands working on Apollo would still be working (just as they were with Shuttle, but not losing a decade of launches).

Yes cphite, I know the lack of gravity issue is a thorny one for long-term spaceflight. My guess is that once the gravity well is no longer an issue humanity will do what Darwin and Wallace said all things do and evolve to adapt to long-term zero G environments. Whether that's a natural process or an artificial process and the speed thereof depends on your choices in SF authors. That said, until we fix the gravity well problem we simply won't have enough experience with long-term zero G to come to any lasting conclusions or fixes. We can posit many things but until the gravity well is no longer such an expensive boundary and we can afford to send up much more than a small tightly-selected group of humans we have no basis for a long-term solution.

Look, I am a child of Apollo and watched Neil come down the ladder. I thought at the time that that was just the beginning of man's explosion/exodus into space. The follow-up was a cruel lesson.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 5:38 pm

superjawes wrote:Okay, my understanding of gravity wells might be a little rusty/off, but it was my understanding that even if you were on the moon, you were technically still in Earth's gravity well.

The trick to getting into staying in space isn't about getting so far away that the gravity doesn't affect you, but moving fast enough to get into orbit. Anything getting out of Earth's gravity well probably isn't coming back, like the Voyager probes and the Curiosity rover.

And you are correct. Here's a very mathy derivation of escape velocity:

https://en.wikipedia.org/wiki/Escape_velocity

It's 11.2 km/sec (roughly 25,000 MPH) just to get out of Earth's well. To escape the Sun's well from Earth requires 42.1 km/s (or 94,175 MPH). Today we can launch something that directly escapes Earth's gravity well (New Horizons). We have no proven way of escaping the Sun's gravity well directly, we need to scrounge every erg of gravitational assist we can find on our way through the gas giants to get there (a/k/a Pioneer 10/11, Voyager 1/2, and New Horizons).

Oh, BTW, you still need an addtional 1.4 km/sec (3132 MPH) if you're on the Moon and want out of Earth's gravity well. There's a reason why modern hard sci-fi is all about the Δv calcuations.

EDIT: Here's a 1954 story on the cold & hard facts of Δv. It was mighty controversial when first printed by John Campbell in Astounding Science Fiction.

http://www.spacewesterns.com/articles/105/
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Re: Russian space shuttle story at ArsTechnica

Postposted on Thu Sep 26, 2013 10:44 pm

Mr. Eco wrote:You do advise others of reading and understanding Russian texts about Buran, yet you posted a link to a page that does not contain anything related to Buran - it is just about the policy of catch up.


My dear friend, I believe in an intelligence of most of the forum readers here and I believe that they are perfectly capable of finding such information by themselves. If you do not - how about helping them by yourself? Such as by pointing them out at, for example, this page:
http://buran.ru/htm/os-120.htm
and using quotes, such as these:

"Тем не менее, несмотря на большую загруженность текущей тематикой, наши ведущие НИИ в МОМ, МАП и Министерства обороны (МО) внимательно отслеживали ведущиеся в США работы по МКС. Проведенные в рабочем порядке проработки показали, что такая система существенно проигрывает по экономичности выведения полезных грузов на орбиту обычным одноразовым ракетам-носителям и не дает особых преимуществ в военном отношении. Более того, надежность многоразовых комплексов с ростом количества проведенных пусков снижается, в то время как у одноразовых ракет-носителей увеличивается."

and perhaps even roughly translating them into English language, such as:

"Even with a highly busy schedule and high amount of current projects, our leading scientific institutes of Ministry of Defence and Ministry of Aviation Industry have been carefully following the USA's development of "reusable spacecraft system" program. Our performed studies have shown that such system is significantly worse in terms of financial viability of launching the various payloads compared to conventional single-use transport ships and does not provide significant advantages in terms of military usage. Furthermore, the reliability of reusable spacecraft systems decreases as the number of its launches increases" and so on.

Surely such activity would be more helpful rather than calling people "arrogant", "dick" and using other personal attacks?

Mr. Eco wrote:It is the russian scientits that designed Buran, not the central committee of the Communist party.

Absolutely. But it is not these scientists who have benefited from that development, nor the common people. That was my actual point. And also the point of the previous links from previous posts. And yes, this is more of a "political" subject BUT when it comes to most of such "impressive" :roll: developments from such specific country you cannot objectively separate these two things.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 12:53 am

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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 2:53 am

clone wrote:
Cphite wrote:But the claim was this: "It isn't the lack of artifical gravity in space that's the problem, it's the abundance of natural gravity keeping us of out of it. "

And that simply isn't a true statement. The act of putting people into space is wildly expensive, yes; but it's not the primary thing that's holding us back from establishing a true foothold in space. And with continued innovation, there is every reason to expect that the costs of putting people into space should come down.

It is much less likely that we are going to see advancements that solve the problems of long term stays in micro-gravity.
the fact that we have space tourism is a solid argument against the cost of getting into space as being the primary issue. the costs are being overcome. (even the private corporation SpaceX is sending cargo up to the space station)

living in a low to negligible to nonexistent gravity environment for prolonged periods has proven what I believe to be "the" major hurdle with no readily available solution.


Space travel is always going to be very expensive no matter how you slice it. The choice you what kind of launch vehicle, propulsion and apparatus you would want go with and consider their pros and cons.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 5:37 am

clone wrote:while I'm not trying to cause a problem I am trying to figure out how to work my way around this forum which at least on the surface seems to be growing more challenging.


Don't worry, I've been duly and appropriately chastised.

I'll try to not make the forum more challenging. But if you want to figure me out, however, that's simple: Don't say things that aren't true. I went off the handle, but you got my attention because you blatantly denied saying something you just said in your previous post.

cphite wrote:There are a total of three who have spent a continuous year in space, and a few others who have come close to a year. However, evidence exists that spending much more than that could result in loss of bone and muscle mass, problems with vision, and various other health issues.


And there were only a total of 24 men who've EVER gone beyond low earth orbit. And no one has done so in the last four decades.

That's what Captain Ned is getting at with the December 1972 thing: there isn't any reason for man to spend long amounts of time in space. There's nowhere to go, nothing to do, except aimlessly float around in LEO. So, given those constraints, why even bother to try and figure out the long-term human endurance of zero-g?

cphite wrote:The price has and will continue to come down as space flight becomes more common and the equipment and procedures become more standard. Humans aren't likely to become more capable of withstanding long periods of zero gravity.


Except that the price is almost entirely the same, with us being unwilling to pay it.

And what you are saying about the lack of advancement in dealing with zero-g isn't true. They are trying to deal with it. But, as I said, there isn't a whole lot of point or interest at the moment. There isn't any real need yet.

http://www.nasa.gov/mission_pages/stati ... 1_prt.html


cphite wrote:You do understand what science fiction means, right? Heinlein was a visionary, yes; but he was still writing fiction


But what he was saying was entirely based in science.

cphite wrote:Or hell, why not just grab a couple of Star Trek novels... it's only a matter of time before we have teleportation, warp drive, and energy shields...


That really isn't a fair comment about Clarke.

http://lakdiva.org/clarke/1945ww/

A space elevator may be infeasible, but it's not impossible like star trek science-fantasy.

cphite wrote:Correct. The rocket science aspect is fairly well settled. It's the medical stuff that's the real challenge.


It's settled, and damning. As Captain Ned says, the physics behind chemical rockets is extremely dismal, to the point where without something better they are plainly impractical.

Captain Ned wrote:That, and launching 50+ times per year. How anyone ever believed the projected Shuttle launch rates is a mystery.


Which is exactly what JohnC was pointing out, that the Russians knew it was a fantasy back in the 70s, and yet they went ahead with Buran anyway.

Which, if we are paying attention, should tell us something.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 8:18 am

clone wrote:the fact that we have space tourism is a solid argument against the cost of getting into space as being the primary issue.

If you're talking about Branson & Virgin Galactic a recreation of Alan Shepard's suborbital Mercury flight isn't any indicator of the cost issue getting fixed. It's an airplane that happens to be able to reach 100 km altitude and can't come close to the speeds needed for orbit. SpaceShip One barely cracked Mach 3, or roughly 2100 MPH, and SpaceShip Two is designed for 2500 MPH. Orbital speed is 17500 MPH. There's a vast dollar gap between the two. Altitude is not the key rocket problem. Speed is.

OTOH, if you're talking about the $20 million Russia charges tourists to fly to the ISS, just remember that their launcher first flew in 1957 and the development costs have long been amortized. If we'd standardized on the Saturn family back in the '60s and stuck with it we'd see similar economies of scale.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 8:31 am

Captain Ned wrote:If you're talking about Branson & Virgin Galactic a recreation of Alan Shepard's suborbital Mercury flight isn't any indicator of the cost issue getting fixed. It's an airplane that happens to be able to reach 100 km altitude and can't come close to the speeds needed for orbit. SpaceShip One barely cracked Mach 3, or roughly 2100 MPH, and SpaceShip Two is designed for 2500 MPH. Orbital speed is 17500 MPH. There's a vast dollar gap between the two. Altitude is not the key rocket problem. Speed is.

The other obvious factor here is getting the right engines. I doubt planes will never get to orbital speeds because jets need a constant feed of oxygen that runs out as you gain altitude, and having a jet try to carry rocket boosters up to 100km would be very, VERY difficult.

So obviously you need rockets to reach 17500 MPH, and that means carrying fuel and O2, in liquid form.

The only way that you could really reduce costs, IMO, is salvaging as much as possible. SpaceX's Grasshopper might be a neat idea, as would considering recoverable solid rocket boosters like the space shuttle did. However, that still increases fuel costs as opposed to reducing them, since you'll have to bring extra fuel accounting for the added weight, even if it's just for parachutes. Not to mention that you also have to keep these things in good repair, as opposed to stages that just need to work once.

Also, for a cool fuel perspective, check out the tank for the US space shuttle. That big orange tank is what it took, in parallel with two boosters, to get the shuttle into orbit.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 8:45 am

ChronoReverse wrote:Multiple engines means better redundancies but it also means greater complexities (the plumbing is difficult).

And sometimes you don't even get redundancies, just additional points of failure.
IIRC the Soviet N1 rocket failed every time, and mostly because it was so hard to synchronize all 30 of its engines.

Redundancy assumes the whole will still work even if one or two components fail, but historically rockets have shown otherwise. Any failure usually means the entire vehicle explodes, or is sent into an uncontrollable spin and then explodes.

Glorious wrote:It's settled, and damning. As Captain Ned says, the physics behind chemical rockets is extremely dismal, to the point where without something better they are plainly impractical.

I feel that's as yet a bit unfair to chemical rockets. All of these maths tend to assume launching a giant rocket from earth, where it has to lift itself, its fuel, and its payload from a gravity well, and against atmospheric friction.
If we were to build a chemical rocket in space, and it was to set off in a place with zero gravity and friction then it wouldn't need to be quite as inefficient as a terrestrial launch.

To put things into perspective, solar sails, which are scientists are giving pretty serious consideration to, takes a very low amount of force. Let's say 1 Nm, if wikipedia is to be trusted. The first stage of Saturn V is good for over 34 million Newtons. If we were to start a full Saturn V from LEO, I assure you it would get very far, and very quickly.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 9:07 am

jihadjoe wrote:If we were to start a full Saturn V from LEO, I assure you it would get very far, and very quickly.

And absent a space elevator or similar device, the cost of assembling a Saturn V in LEO with all of the concomitant heavy-lifter launches to get parts & consumables to LEO would quickly render the entire idea a farce. About the only possible benefit is that you would no longer need to design the first stage F-1s for atmospheric flight, which would increase their Isp by about 40 points [/handwave].
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 9:16 am

Glorious wrote:That really isn't a fair comment about Clarke.

http://lakdiva.org/clarke/1945ww/

If only he had a patent attorney close to him. I can't imagine the potential value of a patent on the concept of the geosync comsat. There's a reason it's called the Clarke Belt.

IIRC he also did WWII work in blind-landing radar applications and turned that into one of his short stories.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 9:28 am

Captain Ned wrote:If you're talking about Branson & Virgin Galactic a recreation of Alan Shepard's suborbital Mercury flight isn't any indicator of the cost issue getting fixed. It's an airplane that happens to be able to reach 100 km altitude and can't come close to the speeds needed for orbit. SpaceShip One barely cracked Mach 3, or roughly 2100 MPH, and SpaceShip Two is designed for 2500 MP


Heck, the US definition of "space" (or at least "astronaut") is only 50 miles up. That's 20 km less. Not a tremendously difficult target.

Strapping a rocket motor to a plane is a complicated engineering problem, but it's not anything particularly new. Those "spaceship" contraptions can just barely make it past the Karman line.

Dragon is far more conventional, and the space tourism plans, unsurprisingly, don't revolve around it. It is considerably more expensive to go those extra few hundred kilometers up. The target launch price for a crewed (and considerably cramped) Dragon capsule is like 20 million per seat. That's seen as "low-cost."

Captain Ned wrote:There's a vast dollar gap between the two. Altitude is not the key rocket problem. Speed is.


Yep. And Tsiolkovsky's equation makes that expensive. You want high delta-V? M0 is going to have, erm, skyrocket. We only have so much control over M1, staging helps (but adds considerable complexity, risk, and expense), but the thing still has to be safe and structurally stable. You can only cut so much non-propellant weight because your space-seeker needs to ride something. Likewise with Ve, even with esoteric (and thus likely volatile, toxic, expensive) chemistries there still isn't all that much improvement to be had.

Like we said, the physics are damning.

Captain Ned wrote:OTOH, if you're talking about the $20 million Russia charges tourists to fly to the ISS, just remember that their launcher first flew in 1957 and the development costs have long been amortized. If we'd standardized on the Saturn family back in the '60s and stuck with it we'd see similar economies of scale.


And even then, since the Russians were contractually obligated to provide many, if not all, of those Soyuz flights to ISS for re-crewing purposes, the cost was nominal. Once that ended, the tourism did too. Now, the Russians charge the US something on the order 60-70 million per seat for our astronauts, which is probably far more reflective of the actual cost.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 9:32 am

Captain Ned wrote:About the only possible benefit is that you would no longer need to design the first stage F-1s for atmospheric flight, which would increase their Isp by about 40 points [/handwave].


Mainly in that you could fuel them with LOX/LH instead of LOX/RP-1, since you wouldn't need the extra kick the kerosene gives to get started.

I'm not convinced that a full 3-stage Saturn V starting from LEO would be better than simply replacing the third stage with a NERVA engine and making the first two stages powerful enough to get the stack into orbit without the 3rd's assistance, especially once you figure in the cost, time, and annoyance of assembling the V in orbit and getting everything up there.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 9:46 am

bthylafh wrote:Mainly in that you could fuel them with LOX/LH instead of LOX/RP-1, since you wouldn't need the extra kick the kerosene gives to get started.

LOX/LH2 - Isp sea level 363 - Isp vacuum 452 (SSME)

LOX/RP1 - Isp sea level 265 - Isp vacuum 304 (F-1)

There's no extra "kick" in RP1. What there is is an acceptable Isp at an acceptable mass fraction. Beside the fact that a 1.5 millon lbf LOX/LH2 engine was far beyond early 1960's rocket tech, the resulting massive increase in the structural size and weight of the S-1C (Saturn V first stage) would have doomed the entire concept. LOX/RP1 is used in first stage boosters because RP1 is far more dense than LH2 and allows for smaller structural designs. Modern boosters do use LOX/LH2 in their first stages but, if you look closely, they all have "stage zero" strap-ons to get the bloody thing off the pad.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:05 am

Sidebar: I don't remember it being specifically mentioned in this discussion, so for anybody who is not already aware and who might be interested in reading about NASA's next heavy-lift platform, the Space Launch System, go here: http://www.nasa.gov/exploration/systems/sls/index.html#.UkWeFleiLCQ

The "Read More" link at the bottom of the page links to a PDF.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:15 am

Lucky Jack Aubrey wrote:Sidebar: I don't remember it being specifically mentioned in this discussion, so for anybody who is not already aware and who might be interested in reading about NASA's next heavy-lift platform, the Space Launch System, go here: http://www.nasa.gov/exploration/systems/sls/index.html#.UkWeFleiLCQ

The "Read More" link at the bottom of the page links to a PDF.

A full discussion of the SLS is clearly an R&P topic as its prime goal is avoiding the mass layoffs required by the end of the Shuttle program. I shan't go further here in the 'Porch.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:21 am

Lucky Jack Aubrey wrote:Sidebar: I don't remember it being specifically mentioned in this discussion, so for anybody who is not already aware and who might be interested in reading about NASA's next heavy-lift platform, the Space Launch System, go here: http://www.nasa.gov/exploration/systems/sls/index.html#.UkWeFleiLCQ

The "Read More" link at the bottom of the page links to a PDF.

I just have to say that it is extremely cool to see something that incorporates elements from the Saturn rockets and the shuttle launch in one package :D
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:29 am

Captain Ned wrote:
bthylafh wrote:Mainly in that you could fuel them with LOX/LH instead of LOX/RP-1, since you wouldn't need the extra kick the kerosene gives to get started.

LOX/LH2 - Isp sea level 363 - Isp vacuum 452 (SSME)

LOX/RP1 - Isp sea level 265 - Isp vacuum 304 (F-1)

There's no extra "kick" in RP1. What there is is an acceptable Isp at an acceptable mass fraction. Beside the fact that a 1.5 millon lbf LOX/LH2 engine was far beyond early 1960's rocket tech, the resulting massive increase in the structural size and weight of the S-1C (Saturn V first stage) would have doomed the entire concept. LOX/RP1 is used in first stage boosters because RP1 is far more dense than LH2 and allows for smaller structural designs. Modern boosters do use LOX/LH2 in their first stages but, if you look closely, they all have "stage zero" strap-ons to get the bloody thing off the pad.


Well, /yes/. That's the long-winded and pedantic way of saying what I did: for the purposes of the first stage, RP-1 gives more power and is more desirable.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:29 am

superjawes wrote:I just have to say that it is extremely cool to see something that incorporates elements from the Saturn rockets and the shuttle launch in one package :D

Indeed - that was the first thing that grabbed my attention.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 10:31 am

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Last edited by clone on Tue Jan 14, 2014 3:10 am, edited 1 time in total.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Fri Sep 27, 2013 11:19 am

bthylafh wrote:for the purposes of the first stage, RP-1 gives more power and is more desirable.

RP1 does not give more power as seen by the specific impulse ratings. What it does is give acceptable power efficiency in the available mass/size budget.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Sat Sep 28, 2013 12:18 am

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Last edited by clone on Tue Jan 14, 2014 3:04 am, edited 1 time in total.
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Re: Russian space shuttle story at ArsTechnica

Postposted on Sat Sep 28, 2013 7:10 am

Captain Ned wrote:
jihadjoe wrote:If we were to start a full Saturn V from LEO, I assure you it would get very far, and very quickly.

And absent a space elevator or similar device, the cost of assembling a Saturn V in LEO with all of the concomitant heavy-lifter launches to get parts & consumables to LEO would quickly render the entire idea a farce. About the only possible benefit is that you would no longer need to design the first stage F-1s for atmospheric flight, which would increase their Isp by about 40 points [/handwave].


Possibly farcical, but it does make possible missions that would otherwise not be doable with a terrestrial launch. I read somewhere that Saturn V was about as big as they could build a rocket then, because of limits imposed by structural strength. Any bigger than that, say a manned Mars mission with a return capable lander and command module, would almost certainly require some assembly to happen in orbit.

Wasn't the shuttle supposed to be the vehicle that enabled all this? Cheap, routine flights into space, they said.
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